Box strapping tool



May 28, 1949. H. c. DOOLITTLE BOX STRAPPING TOOL 2 Shets-Sheetl OriginalFiled June -14, 1937 Q Q f? w? p ZIWWW HOWARD 6717001317725 May 28 1940-H. c. DOOLITTLE aox STRAPPING TOOL Original Filed June 14, 1937 2Sheets-Sheet. 2

Patented May 28, 1949 UNITED STATES BOX STRAPPING roor.

Howard C. Doolittle, New Britain, Conn, assignor to The Stanley Works,New Britain, Conn, a corporation of Connecticut Original applicationJune 14, 1937, Serial No. 148,078. Divided and this application June 3,1938, Serial No. 211,541

25 Claims.

This invention relates to a tool for tensioning metal straps aboutpackages, boxes, or other articles and for maintaining the straps undertension while they are being secured in tensioned relation.

The aim of the invention is to provide an improved tool by means ofwhich straps may be more quickly tensioned With greater facility aboutboxes and the like and the tension maintained while the straps are beingsealed or otherwise secured.

To these ends, there is provided a simple, compact, easily portable,sturdy, and effective machine by means of which the straps may be veryquickly tensioned to the desired degree with relativelyslight effort andthe tension maintained during the sealing operation. The tensioningdevice shown herein may be used with the sealing device shown in myco-pending application, Serial No. 148,078, filed June 14, 1937, inwhich the tensioning device is shown in conjunction with the sealingmeans; this application being a di-.

vision of said prior application. The machine, however, can be readilyused with any type of sealing means, which means may be either carriedon the same base or may be separate therefrom.

The improved machine has many features of novelty and advantage, isrelatively small, compact, and of light weight, and may be readilyoperated to apply binding straps about packages, boxes, or the like,under any desired tension. The machine is further designed to permit itto be readily used with suitable types of sealing means.

Other objects will be in part obvious and in part pointed out more indetail hereinafter.

The invention accordingly consists in the features of construction,combination of elements, and arrangement of parts which will beexemplifled in the construction hereinafter set forth and the scope ofthe application of Which will be indicated in the appended claims.

In the accompanying drawings:

Figure 1 is a side elevation of the invention showing the partspositioned with a strap fully tensioned;

Fig. 2 is a sectional side elevation in a reverse position to Fig. 1;the position of the parts prior to the tensioning being indicated bydotted lines;

Fig. 3 is a section on the line 33 of Fig. 1;

Fig. 4 is a sectional view taken substantially along the line 4-4 ofFig. 1;

Fig. 5 is a front end view of the frame and parts taken substantiallyalong the line 5-5 of Fig. 1;

Fig. 6 is a view partially'in section taken on the line 6-45 of Fig. 3;

Fig. 7 is a fragmentary view showing the for- 5 ward strap guidemember;- and Fig. 8 is a fragmentary rear view of the movable stopmember.

In accordance with the present invention, there is provided a tensioningdevice comprising a frame H] which has a substantially flat bottom facell supporting the tool on a box or other article about which a strap Sis to be tensioned with its ends S and S" threaded through thetensioning device, the end S overlying the end S. The base is providedadjacent therear end thereof with a laterally projecting foot I2 havingasubstantially fiat strap supporting face I3. A dog it cooperates withthe foot to rigidly secure one end S of the strap S to the frame duringa tensioning operation; the dog having a laterally extending flange 15,the lower face thereof being parallel to and overlying the upper face l3of foot 12 and provided with a plurality of strap engaging teeth.

The flange 15 projects from the lower end of an arm l6, which armdependsfrom a laterally extending cylindrical shank I! journalled in a bore l8of the frame Ill. Arm [6 is angularly movable within a substantiallytriangular shaped recess l9; the arm having a curved upper end in matingslidable engagement with the curved upper surface of the recess, whichsurface forms a partial continuation of the surface of the bore 18 toaid in receiving thrusts when the strap end S is gripped by the dog Magainst the foot l2. The arm 16 is angularly disposed towards theforward end of the frame with reference to a vertical plane through theaxis of the shank l I and the bottom so that a clockwise rotation of dog14, as viewed in Fig. 1, moves the flange 15 into tighter strap grippingengagement. A spring 22 interposed between the forward wall of recess 19and dog It further aids in urging the dog into strap gripping engagementand cooperates to prevent any slipping of the strap end S toward therear of the frame during a tensioning operation. The extreme outer endof flange I 5 has an upwardly projecting lip 20, whereby there isprovided on the upper'surface of the flange between the lip and the arm18 a channel or groove 2! for receiving and guiding the opposite strapend S as hereinafter pointed out.

The frame 10 is provided forwardly of foot 12 with a recess 23 acrosswhich the strap parts to place the strap under tension. similar inoperation to dog I4 but grips the strap end S" in opposed relation tostrap end S and able strap guide I95.

are drawn and wherein they overlie to permit the sealing and cuttingoperations to be performed by any suitable sealing and cutting means. Afoot 24 extends laterally from the frame at the forward side of recess23 and provides a support for the forward strap end S of the strap S. Inorder to prevent the strap end S from riding over foot 24, there isprovided a bladelike stop member 99 pivotally mounted so that its loweredge 9| rests on the top surface 25 of foot 24 and the forward surfaceof the member 99 is at right angles to the top surface 25. The inner endof blade 99 is provided with an upwardly facing shoulder 92 which fitsbeneath an outwardly projecting shoulder 93 on the rotatable bladecarrier 94 which is mounted in the circular opening 95 in the frame I9and to which the blade is secured by the rivet 94. The blade carrier 94is cut away to provide rearwardly extending wing members 91 havingdownwardly facing shoulders 91', between which there is located theupper end of a pin 98. The lower end of the pin has an enlarged head 99which is screw-threadedly secured in the frame 19. The downwardly facingshoulders 91' and Wings 91 provide stops for one end of a spring I99which is mounted on the pin 98 between the shoulders and the enlargedhead 99 of the pin. The spring tends to rotate the merifiher 94 andblade 99 in a counterclockwise direction to stop position with the loweredge 9| thereof in engagement with the foot 24. The pin 98 furtherserves to maintain the blade carrier 94 positioned within the circularopening 95 of the frame ID. The forward end of the blade 98 is providedwith a cam surface I9I to permit the opposite end S" of the strap S tobe slid beneath the blade and lift the stop against the tension of thespring I99 as it is drawn through the device to overlie the strap end S.

grip the opposite strap end S" of the strap S and to be movedlongitudinally within the frame Dog 21 is is angularly disposedrearwardly of a plane "through the axis of a supporting shaft 29 upon'which it is mounted at its upper end. Shaft 29 is mounted in head 28,and the dog 21 has a rounded upper end slidably engageable with arounded flange 39 projecting outwardly from head 28 to cooperate withshaft 29 in receiving thrusts imparted upon the dog during a strapgripping operation.

The bottom of dog 27 is provided with strap gripping teeth 3I disposedabove a strap supporting face 32 of laterally projecting foot 33. Thereis interposed between the depending rear wall 34 of the flange 39 andthe dog 27 a spring 35 normally urging the dog into strap grippingposition. Located forwardly of the dog and positioned beneath thedepending forward wall of flange 39 is a removable and rotatable adjust-The strap guide is generally in the form of a T-headed pin having arounded body portion I95, the inner end of which is received within abore I 97 in the head 28 and secured therein by a set screw I99 whichprojects into a groove I98 in the body portion ,of the pin. The roundedhead H9 of the pin is connected to the body part I95 by a shoulder IIIwhich tapers outwardly from the body portion to the periphery of thehead and thus forms a lip extending downwardly and outwardly from thebody portion I99 and is so spaced from the side wall of head 28 todefine a channel or groove 39 adapted to receive the strap end S andlocate it beneath the dog 21. As the surface of member I95 becomes wornor scored due to the tensioning of the strap, the set screw I99 may beloosened and the member I95 turned to pre sent a smooth rounded surfaceover which the strap is guided. When the entire surface of member I95becomes worn, a new pin may readily be substituted to provide a newguide surface and thereby eliminate any wearing or scoring of thepermanent parts of the frame 59 or head 29.

The head 28 is slidable in a recess 39 in the forward end of the frameand is positioned therein by a tensioning rod II which fits within abore 52 within the head 28; the rod having a reduced portion 93extending through the head and provided with a threaded portion adaptedto receive a nut 44 to secure the head 28 against the shoulder 45 of thetensioning rod at the end of the reduced portion.

The rod l! is slidably mounted in abo're 46 which terminates at a recess41 at the rear end of the frame. The rearward end of the tensioning rodhas a reduced portion 39 slidably extending through a bore 49 in aplunger 59; .the plunger 59 being mounted for longitudinal slidablemovement in a recess i'I in frame [9 and being prevented from rotationtherein by a key 5! received within a key slot 52 in the wall of theframe 19.

The rearward end of the rod ll is provided with an adjustment screw 53having an enlarged head 54, and mounted intermediate of the head 54 andthe rear wall of the plunger 59 is a coiled spring 55 which normallymaintains the inner end of plunger 59 abutting against the shoulder 56at. the inner end of the reduced portion 49 of the rod 45. Thetensioning rod is movable longitudinally within the frame by atensioning lever 57, which lever is journalled at its inner end upon ashort shaft 58 having flattened outer ends 59 slidably and nonrotatablyreceived Within slots 89 in the frame; one slot being shown in Fig. 3and the other lying above the cut away portion 6| of the rod 5|. Theoperative end of the tension lever 57 is formed as a gear segment 62,which segment is adapted to mesh with a rack 63 rigidly secured to thebottom of the frame by rivets 64.

The lever 51 is interconnected by a link 95 to the plunger 59; the linkhaving its forward end 5 85 journalled in a recess 65 in the lever 57;the recess being located to the rear of the shaft 58 and having an uppershoulder 81 arranged to abut the top of the link '65 to limit the linkmovement in one direction and hold the link in position. The oppositeend of link 65 has a laterally projecting pivot 98 journalled within abore 69 in the forward end of the plunger 59.

From the foregoing it will be seen that as the upper end of the lever 57is moved rearwardly it 1 against spring 55 and bolt 56 to thus shift thetensioning rod 4| longitudinally in the frame and draw head 28rearwardly from the dotted line position to the full line position shownin Fig. 2. The forward end 85 of the toggle link 65 is thus rotated froma plane above the pivot of lever 51 until it reaches a point wherein thetoggle, comprising the link 65 and that portion of the operating leverbetween the shaft 58 and the link end 85, approaches a straight linewhich passes through the centers of the pivotal ends of the link 65 andshaft 58, thus greatly multiplying the energy exerted by the operator.and obtaining tremendous power with slight effort during the finalportion of the tensioning operation. If at any time the tension exertedon the strap should overcome the force exerted, further movement of thetensioning lever 5'! will force the plunger rearwardly to compress thespring 55 without moving the rod 4|; the actuating lever thus being, ineffect, flexibly connected to the tensioning rod 4!.

As the operating handle 5'? is brought to its extreme rearward andbottom position, the pivot 85 passes through dead center and below thepivot of the lever 5'1, with the result that the parts are automaticallylocked in position with shoulder E! of the lever recess 66 overlying thelink. As the tension of the strap tends to move the plunger 59 forwardlyand the line of thrust through the link 65 is between the axes of thetensioning lever 51 and the rack '53, the segment cannot move forwardlydue to its meshing engagement with-the rack. During this final movement,the plunger 50 will move. rearwardly away from the shoulder 56 of therod 4|, placing the spring 55 under compression; at which time the pivot85 is beneath dead center and the compression of the spring urges theshoulder 67 tightly against the link 65 to lock the lever 51 intensioned position.

As it is not always desirable to take up all the slack with a singlestroke of the lever 51, there is provided a supplemental dog pivotallysupported on its upper end on a shaft H to the rear of and above shank Hof dog M. The dog it has on its lower face a tooth portion 12 overlyinga projection 13 and adapted to cooperate therewith to grip the strap.The dog H! is angularly disposed generally similar to dog 2'1, and thestrap supporting projection 13 is located rearwardly and slightly abovethe channel or groove 2! of the dog M. The tooth face l2 of the dog itis normally urged into gripping engagement by a suitable spring Mmounted on the end of a stud l5 carried on the frame It. The dog iiicooperates with dog 21 in the capacity of a ratchet to prevent releaseof take-up of strap end S" by the movement of the head 28. Thus, if thetension lever is swung upwardly'to move the dog 27 away from the dogIii, the previously accumulated tension on strap S is maintained by dogIll. Similarly, during the following downward movement of lever 51 thedog 21 again grips the strap end S to provide further tensioning of thestrap which now freely slides over the groove 2i and under dog It; thedog Hi preventing any loss of slack upon opposite movement of thetensioning lever 51.

It will be seen from the foregoing that with sion is not obtained, byoscillating lever 51 any desired degree of tension may be obtained, and

should the tension become too great thedevice will act to compress thespring 55 without moving the head 28 and thus prevent breakage of the 5strap.

As many changes could be made in the above construction and manyapparently widely different embodiments of this invention could be madewithout departing from the scope thereof, it is '10 intended that allmatter contained in the above description or shown in the accompanyingdrawings shall be interpreted as illustrative and not in a limitingsense.

It is also to be understood that the language used in the followingclaims is intended to cover all of the generic and specific features ofthe invention herein described and all statements of the scope of theinvention which, as a'matter of language, might be said to falltherebetween.

I claim as my invention;

1. In a box strappingtool, a frame, a strap lock for securing one end ofa strap thereto, a,

member slidable in the frame, a strap lock carried by said member andarranged to hold the other end of the strap and to be moved relative tothe first mentioned lock for a strap tensioning operation, a rack fixedto the frame, a tensioning lever having a gear segment enmeshed withsaid rack, means movably maintaining said lever in enmeshed rollingengagement with the rack, and a toggle connection between said lever andsaid member.

2. In a box strapping tool, a frame, a strap lock for rigidly securingone end of a strap thereto, a member slidably mounted in the frame, astrap lock carried by said member and arranged to hold the other end ofthe strap and to be moved relative to the first mentioned strap :40

look, a tensioning lever having a movable pivot, a rack fixed to saidframe, said lever having a gear segment enmeshed with the rack, and atoggle connection between said lever and said member and adapted toapproach a straight line .45

position during the final tensioning movement of said lever.

3. In a box strapping tool, a frame, a strap lock for securing one endof a strap thereto, a

member slidable on the frame, a strap lock carried .by said member andarranged to hold the other end of the strap and to be moved relative tothe first mentioned lock for a strap tensioning operation, a rack fixedto the frame, a shaft disposed transversely of the movement ofsaidmember and supported in the frame for movement substantially in theline of movement of said member, a tensioning lever mounted on saidshaft and having a gear segment in enmeshed rolling engagement with therack, and a link pivotally connected between the lever and said member.

4. In a box strapping tool, a frame, a strap lock for holding one end ofa strap thereto, a

member slidable in the frame, a strap lock car- 1 ried by said memberand arranged to hold the other end of a strap and to be moved relativeto the first mentioned strap lock for a strap tensioning operation, arack rigidly secured to the frame, a tensioning lever having a gearsegment enmeshed for rolling engagement on the rack, and a toggleconnect-ion between the lever and said member for transmitting movementtherebetween and adapted to be swung by the lever past a dead center toa locked position. I

5. In a box strapping tool, a frame, clamping means for holding one endof a strap to the frame, a member slidably mounted in the frame,clamping means carried by said member and arranged to hold the other endof the strap, a rack secured to the frame, a tensioning lever having agear segment enmeshed with said rack, means securing said lever forenmeshed rolling engagement on the rack, and a toggle connection betweenthe lever and said member arranged to be shifted through a dead centerposition by the lever, and a shoulder on said lever engaging said toggleafter it has shifted through dead center position for limiting furthermovement thereof.

6. In a box strapping tool, a frame, a strap lock for securing one endof a strap thereto, a member slidable in the frame, a strap lock carriedby said member and arranged to hold the other end of the strap formovement relative to the first mentioned strap look, a rack secured tothe frame, a tensioning lever mounted for pivotal slidable movement inthe frame and having a gear segment enmeshed for rolling movement on therack, a toggle connection between the lever and said member, andresilient means between the toggle and said member arranged to yieldwhen the strap has been brought to a predetermined tension.

7. In a box strapping tool, a frame, a strap lock for securing one endof a strap thereto, a member slidable in the frame, a strap lock securedto said member and arranged to hold the other end of the strap formovement relative to the first mentioned lock, a rack fixed to theframe, a tensioning lever movably supported in the frame and having agear segment enmeshed in rolling engagement with said rack, means foroperatively connecting said member and lever, means on the leverincluding a sleeve slidably mounted on said member rearwardly of saidlever, a link having its ends respectively pivoted on said lever and theadjacent end of said sleeve, and resilient means disposed between theother end of said sleeve and said member.

8. In a box strapping tool, a frame, a strap lock thereon for holdingone end of a strap, a tension rod slidable in the frame and having areduced end provided with a shoulder, a strap lock carried by the otherend of the rod for holding the other end of the strap and movabletowards said first look for tensioning the strap, a rack on the frame, atensioning lever movably supported in the frame and having a gearsegment enmeshed with said rack, a plunger slidably mounted on thereduced end of the rod, a link pivotally connected to the plunger and tosaid lever, and a spring between the plunger and the rod tending tomaintain the plunger against said shoulder, said spring yielding whenthe strap is brought to a predetermined tension to prevent strapbreakage.

9. In a box strapping tool, a frame, clamping means for holding one endof a strap thereto, a member slidably mounted in the frame, clampingmeans carried by said member for holding the other end of the strap, arack secured to the frame, a tensioning lever having a gear segmentenmeshed with said rack, means securing said lever for enmeshed rollingengagement on the rack, an operative connection between the lever andsaid member including spring actuated means mounted on said member, atoggle connection between the lever and said spring actuated meansarranged to be shifted through a dead center position by said lever, anda shoulder on said lever engaging said toggle after it has shiftedthrough dead center position for limiting further movement thereof.

10 In a box strapping tool, a frame, clamping means for holding one endof the strap thereto, a tension rod slidable in the frame, a shoulder onsaid rod, clamping means carried by the rod for holding the other end ofthe strap, a rack on the frame, a tensioning lever movably mounted inthe frame and having a gear segment enmeshed with the rack, a plungerslidable on said rod and engageable with a shoulder, a toggle connectionbetween the lever and plunger arranged to be shifted through a deadcenter position by the lever, means on the lever abutting the togglewhen the lever is shifted to a predetermined setting past dead centerand limiting further movement thereof, and a spring normally urging theplunger against the shoulder.

11. In a box strapping tool, a frame having a longitudinal recesstherein, a member slidable in the recess, a front strap lock supportedby the member for movement towards and from the frame and adapted toclamp against one end of a strap, a rear strap lock on the framecooperating with said front lock and clamping against the strap endextending through said front lock, and an intermediate strap lockmounted on the frame substantially between said other strap locks andarranged to rigidly secure the other end of the strap to the frame, saidrear strap lock cooperating with the front strap lock to positively holdsaid first mentioned strap end against movement when the front straplock is moved away from the other strap locks to get another grip on thestrap.

12. In a box strapping tool, a frame having a laterally projecting footadapted to support one end of a strap, a dog pivotally mounted in theframe for movement towards and from said foot to grip the strap end, asecond foot forwardly of said first foot, 3, stop associated with saidfoot and against which the free strap end abuts, a second strap lookforward of said second foot and arranged to grip the other end of thestrap and move it relative to said second foot to produce a straptensioning operation, and means to operate said second strap lock.

13. In a box strapping tool, a frame, a rear strap lock comprising afoot extending laterally from the frame and adapted to support a strapend, a pivoted dog cooperating with said foot and engageable with thestrap end, a forward strap lock for receiving the other strap end andmovable relative to said rear strap lock and including a foot and a dogcooperating with the foot and an intermediate foot interposed betweensaid first two mentioned feet and having an upwardly facing surfaceadapted to support the first-mentioned strap end, a pivoted stopassociated with said intermediate foot and having its lower edge inengagement with said upwardly facing surface and its forward face atright angles thereto and against which said strap end is adapted toabut.

14. In a box strapping tool, a frame having a base adapted to rest on afiat surface, a strap lock for holding one end of a st ap thereto, asecond strap lock for holding the other end of the strap and adapted tobe moved longitudinally in the frame, an actuating lever extending abovesaid frame, means mounting said lever in the frame for limited pivotaland longitudinal movement, and means connecting said lever and secondstrap lock, whereupon movement of the actuating lever will move saidstrap lock.

15. In a box strapping tool, a frame having a I base adapted to rest ona fiat surface, a strap lock for holding one end of a strap, a secondstrap lock for holding the other end of the strap, and means for movingsaid second strap lock relative to the first and comprising a leverextending above said frame and means mounting said lever for limitedpivotal and longitudinal movement inthe frame.

16. In a box strapping tool, a frame having a base adapted to rest on aflat surface, a strap lock for holding one end of a strap, a secondstrap lock for holding the other end of the strap and movable in theframe, an actuating lever extending above said frame and means mountingsaid lever for limited pivotal and longitudinal movement in the frame,and a flexible connection between said actuating lever and second straplock.

1'7. In a box strapping tool, a frame having a bore therein, a strapguide comprising a T headed pin having the end thereof received withinsaid bore, and means for locking said pin against rotation in said bore.

18. In a box strapping tool, a frame, clamp-ing means for holding oneend of a strap tosaid frame, a member slidably mounted in the frame,clamping means carried by said member and .arranged to hold the otherend of said strap, a plunger slidably mounted on said member, a springmounted between said plunger and the end of said member, a tensioninglever, means mounting said'lever for pivotal and longitudinal movementin said frame, and a toggle connection between said lever and saidplunger adapted to transfer the movement of said lever to said memberand to move said plunger relative tosaid member when said lever has beenshifted a predetermined distance.

19. In a box strapping tool, a frame, a strap lock for securing one endof said strap thereto,

a member slidable in the frame, a strap lock secured to said member andarranged to hold the other end of the strap for movement relative to thefirst-mentioned look, a rack fixed to the frame, a tensioning levermovably supported in the frame and having a gear segment enmeshed inrolling engagement with said rack, means operatively connecting saidmember and lever ineluding a link, and resilient means intermediate ofsaid link and member.

20. In a box strapping tool, a frame, a tension rod slidably mounted inthe frame, clamping means carried by one end of the rod for holding oneend of thestrap, said rod being provided with a shoulder adjacent theother end thereof, a plunger slidably mounted on the other end of saidrod, a spring normally urging said plunger against said shoulder, atensioning lever, means mounting said tensioning lever for longitudinaland pivotal movement in said frame, and a tog gle connection betweensaid lever and plunger for initially moving said rod to tension a strapand thereafter move said plunger relative to the rod.

,21. In a box strapping tool, a frame, a tension rod slidably mounted inthe frame, clamlping means carried by the rod for holding one end of astrap, said rod being provided with a shoulder adjacent the other endthereof, a plunger slidably mounted on the rod, spring means normallyurging said plunger into engagement with the shoulder, a tensioninglever movably mounted in the frame and having a gear segment, a rackcarried by said frame adapted to be engaged by said segment, a toggleconnection between said lever and said plunger and adapted upon movementof said lever to initially move said tension rod and thereafter movesaid plunger relative to said rod.

' 22. In a box strapping tool, a frame, a rear strap lock mounted onsaid frame for receiving one end of a strap, a forward strap lock forreceiving the other end of the strap, and a member interposed betweensaid strap locks and adapted to support the first-mentioned strap end, apivoted stop associated with said member and having its lower edge inengagement with said member and its forward face at right angles theretoand against which said strap end is adapted to abut.

23, In a box strapping tool, a frame, a rear strap lock comprising alaterally extending foo-t adapted to support a strap end and a pivoteddog cooperating therewith and engageable with the strap end, a forwardstrap lock for receiving the other strap end and including a laterallyextending foot, a dog cooperating with the foot, and an intermediatefoot interposed between said strap locks and having an upwardly facingsurface adapted to support the first-mentioned strap end, and a pivotedstop vertically arranged relative thereto and against which said strapend is adapted to abut to: limit the forward movement thereof.

24. In a box strapping tool, a frame, a strap lock carried thereby, astrap guide positioned forwardly of said lock and comprising a T headedcircular-bodied pin having its inner end supported in said frame, saidpin extending outwardly therefrom to present a rounded surface forguiding said strap to said lock, and means for locking said pin againstrotation in said frame. 1

25. In a box strapping tool, a frame, a strap lock carried thereby, astrap guide positioned forwardly of said lock and comprising a pin ar-HOWARD C. DOOLIT'ILE.

